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Re: 10+MHz SSTC Gate Drive Circuit Finalized



Original poster: "K. C. Herrick" <kchdlh-at-juno-dot-com> 

I tried simulating the circuit (in SIMetrix, -at- 100 KHz) & couldn't get
much out of it!  I thought to change it a bit & submit my schematic, via
hot-streamer, at http://hot-streamer-dot-com/temp/ssdrvr-kch.pdf.

A 20 V pp source drives the xfmr, simulating the "monster" circuit.  In
the top secondary ckt, D1, C2 & Q1 are as before except C1's capacitance
is much reduced (1 uF takes forever to charge; I'd be worried about those
1st few cycles as to MOSFET drive).  The MOSFET/10-ohm branch is replaced
by Q2 and both Q1 & Q2 are driven via the D3/R1 pair.  D3 provides max.
drive for + excursions while R1 limits xfmr current during "-"
excursions.  (Without R1, Q2's b:c junction will short out TX1.)  R3
simulates TX1's resistance & R6 is for parasitic suppression (in the real
ckt).  R2 damps oscillation a bit.

Ken Herrick